Synthesis, spectroscopic, and electrochemical properties of two dyads consisted of tetrathiafulvalene and carbazole

Two donor-σ-acceptor molecules containing tetrathiafulvalene (TTF) and carbazole moieties were synthesized by the reaction of 9-(4-bromo-butyl)-carbazole (1) with 2,6-bis(hexylthio)-3-(2-cyanoethylthio)-7- (methylthio)-tetrathiafulvalene (2) or 2,6-bis(2-cyanoethylthio)-3, 7-bis(methylthio)tetrathiafulvalene (3) in the presence of CsOH·H2O, respectively. The structures of the molecules were characterized by ¹H NMR, ¹³C NMR, MS, and elemental analyses. They showed negligible intramolecular charge-transfer interaction in their ground states as indicated by their UV-Vis spectroscopics and cyclic voltammetry results. Compared with carbazole, their fluorescence was strongly quenched, which implied that a photo induced electron transfer (PET) interaction between TTF and carbazole moieties occurred.